A League of their Own

Ultra-fast drone racing with Cinema 4D and Octane Render.

By Steve Jarratt

Drone racing is an exciting new sport that pits pilots against one another as they guide their aircraft through a series of obstacle courses. Drones are equipped with cameras that send a video feed back to the pilot's first-person view (FPV) goggles, enabling them to steer the craft as if they were actually on board.

For the 2016 TV season, the Drone Racing League needed a promo sequence to introduce the sport, plus a series of broadcast bumpers, leaderboard graphics and digital adverts. The task of creating these fell to Dazzle Ship, a production studio based in Shoreditch in London's East End, whose clients include Adidas, Asics, Bloomberg and Wateraid.

Creative director Alex Donne-Johnson describes how the DRL promotional video required a somewhat deft approach: "On one hand we wanted to educate the viewers about the technicalities of drone racing, and on the other we wanted to add a narrative that amplified the excitement of a race. You have highly skilled pilots, intense racing, crashes and amazingly designed courses. Our role was to look after the channel branding for the forthcoming broadcast series, and the most important part of this was the show opener."

Given that the majority of viewers don't yet understand what drone racing is, the Dazzle Ship team had to tread a fine line to hit the brief. "It's a totally new concept that sits between real world and sci-fi," says Alex. "It's like a computer game with real-world consequences. The problem DRL faces is that people thought it was just a computer game and didn't understand the real-world aspects of players, FPV goggles and highly skilled pilots. The aim of the intro was to educate them but at the same time transport them into a futuristic science-fiction world that represents the experience of drone racing. Too informative and it could be considered mediocre, too sci-fi and people would struggle to understand the concept."

To set the right tone, the sequence begins with a blend of live action footage and convincingly photorealistic CG drones, which grounds the sport in reality. But from there, the viewer is transported into a more conceptual, stylized environment, with sweeping camera moves through neon-festooned racecourses. "The real-world aspects were incredibly important to the narrative, says Alex, "but then we also needed to enhance this to find an abstract way to embody the vibe of a drone race."

He admits that the biggest creative problem was incorporating so many aspects of drone racing within their short schedule. The four-man team had just eight weeks to fulfill the brief. "We actually had quite a short lead time for the level of quality we wanted to achieve. The most important aspect for the client was hitting the broadcaster’s deadline."

To help deliver the project on time, Dazzle Ship employed Octane Render, the unbiased render engine from Otoy. Octane shifts the imaging pipeline from the CPU to the GPU while providing a fast, interactive preview right within Cinema 4D. "The reason we chose Octane was because of the short deadline, says Alex. "We knew that we needed to create proofs-of-concept pretty fast and in some cases do minor tweaks on-the-fly to send back to the client. Octane is very versatile in this respect as it enables you to make changes and render good-quality stills very fast. GPU render farms are becoming more common. However, we did everything locally and got as many GPUs in as possible."

The video begins with shots of the human pilots donning their FPV goggles, complete with the obligatory high-tech overlays and UI elements, which were added in Adobe After Effects. It then cuts seamlessly to the full-CG drones, revving up their rotors and taking off from their launch platforms, complete with a cool slo-mo shot. The drone model was supplied as a 3ds Max mesh but had to be 90% rebuilt to allow for proper texturing and animation in Cinema 4D.

Now airborne, our perspective switches to a drone's-eye view of the course, a futuristic construct of gleaming metal and glowing lights with a distinctly Tron 2.0 feel. "All of the race courses were built in Cinema 4D following strict art direction," explains Alex, "and everything was rendered in Octane for speed, realism and its ability to provide a very high-quality preview in real-time."

The tunnels were created using meshes cloned along a spline, and the tracks were made using a Sweep object with detailed splines to generate the complex forms. To get the nice metallic reflections, an HDRI environment was used with a gradient to provide a sense of variation. "The idea was to keep the lighting as realistic as possible so much of it comes from using emissive textures on things that actually emit light."

The neon effect is a mixture of lights and emissive materials. "Actual lights were used sparingly," says Alex, "mainly to highlight areas that became too dark, but always as naturally as possible. In some ways as you can't use pure black because you risk getting too dark. You need to use a grey and then grade it down in post, if need be. We knew we wanted to keep it dark to really make the light trails pop."

As the drones speed through the sci-fi environment they leave glowing trails in their wake – an effect produced using a fairly unorthodox method. "The light trails were created using Hair objects in Cinema 4D for render speed," explains Alex. "Hair seemed to work very well with Octane and was quite versatile in terms of texturing and lighting. We used emissive materials to create the realistic glow on them. The shots were rendered out with many passes and the scenes were heavily composited in After Effects."

As the drones exit the course they head toward a cityscape, again all modeled in Cinema 4D. The layout was based on a grid by drawing lines that originated from the DRL logo, which is revealed in a pullback at the end of the sequence.

The team rendered out a variety of passes, using an Emission pass to enhance the trails and lights and then Ambient Occlusion, Specular and Lighting passes, depending on the scene. Motion Vector and Depth passes were also used for motion blur and other effects when compositing. "We didn't use Octane's motion blur," comments Alex, "but we did use its depth-of-field on the drone shots at the start of the sequence. It's very quick and powerful. For the rest we decided to keep the control in post-production."

"Octane is an emerging render system with a whole range of settings," he adds, "so the settings for each shot had to undergo a lot of tweaking to get the best result. Rendering locally across different machines, it was important for us to assign the various scenes to each one accordingly. It was labor-intensive to do this but saved us precious render times with the tight deadline. All of the shots were either Direct Lighting or Path Tracing, depending on the kinds of materials we'd used in the scene."

With the rendering complete, work moved to post-production to enhance the overall look and ambience of the shot. "We exported cameras and nulls from Cinema 4D into After Effects and then used [Video Copilot's] Optical Flares. We wanted to keep it very subtle. In terms of the glow it turns out Octane does this very well inside the camera tag. However, we enhanced it slightly in After Effects using render layers."

"Using Cinema 4D in conjunction with Octane gave us a very powerful setup that enabled us to iterate quickly based on our collaborations with an overseas client. Also, because it's fairly new, there is a strong GPU community online that you can get feedback from and troubleshoot issues."

Despite Octane's speedy output, the project still demanded some late nights and long weeks, which had an impact on Dazzle Ships' junk food intake. "We ate quite a lot of burgers during the making of this project," admits Alex, "including one called 'The Devastator,' which has been named Britain's biggest burger and is eight inches high. If timed well you can be in a food coma while waiting for a render."

Steve Jarratt is a long-time CG enthusiast and technology journalist based in the UK.